I was able to use the method suggested by LucD. Since I was installing a Cisco vib for a nexus 1kv using a depot URL, my code looked like below:
$esxcli= Get-Esxcli -vmHost hostname.example.com
$ciscovibpath="/vmfs/volumes/datastore/Cisco_bootbank_cisco-vem-v152-esx_4.2.1.2.1.1a.0-3.0.1.vib"
$esxcli.software.vib.install($null,$null,$null,$null,$null,$null,$null,$null,$ciscovibpath)